Water rises and falls up to 12 yards, twice a day in the Severn Estuary. That’s a lot of potential tidal power going to waste, and the UK knows it. Yesterday, the government announced 5 potential schemes to harness the Severn’s plentiful energy.
The proposals are as follows: the Bridgewater-Bay lagoon (impounds a section of coastal estuary to generate 1.36GW), the Fleming lagoon (a similar scheme on the Welsh shore), the Cardiff-Weston barrage (ten-mile stretch of land that could generate up to 5% of the UK’s energy needs), the Shoots barrage (upstream scheme that could generate 1GW), and the Beachley barrage (scheme above the Wye River that could generate 625MW).
The lagoons would be built from stone, rubble, and 9 ft. high sausage-shaped bags filled with silt. The bags would create a 12 yard high lagoon wall. Each lagoon would theoretically fill with water twice a day, and power would be generated when water flowing out of the lagoons drives electricity-generating turbines.
According to project developers, a prototype lagoon could be built by 2012.
All of the proposed schemes have received environmentalist approval, with the exception of the Cardiff-Weston Barrage. The controversial dam would destroy thousands of acres of mudflats and salt marshes.
The UK government will pick a project by 2010 after a 2-year feasibility study looking into the costs, impact, and benefits of each scheme.
Photo CC licensed by flickr user Simon Pow